Vibrating screen.



R. P. AKINS.

VVIBRATING SCREEN". APPLICATION FILED AUG-31.1914.

Patented Nov. 16, 1915.

mwm

m f w 2% @W W h o M I a M% W eras rnnn n g nnnnnnnn n emits, or nnn'vnn, cononene, nssrenon ro cono'nnno rnon wanna corrrnnr, or nnnvnn, cononano, n oonronnrron vor irnrnn.

vrnrrne scnnnn city for a classifying, grading, or screening hrnptien exists The invention relates more particularly to that class of vibrating screens which are supported in an inclined position and are adapted'to vibrate in a direction approximately at right angles to the plane of the screen surh'ace Screens of'this general type are shown in United States Patents Nos.

"i'3 8fi85, dated eptember 8,! i903 and 8l i,952, dated March 13, 1906. in the former of these patents a screen is provided hit which is sprmg-supported "and is freely poised or heated throughont its entire ex tent so as to vibrate as an entirety. Screens of this type however, being inclined, have a tendency to tilt forward, due to the com binedweight oi the vibrating parts and the,

lead of material passing over the screen,- with the result that they assume a greater degree of inclination than is desired. This brings the upper end of the screen against the stops for limiting its vibration, and all, or-nearly all the vibration takes place the lower end, the upper end thereby losing a part or its eticiency. he order to ob viate this tendency of the screen to rock longitudinally about the point spring and yet at the same time obtain practically all the advantages of the freely Y poised screen'of the earlier patent, the screen litl disclosed in Patent M4952 was provided.

with bars supported at one end to a etationary frame and at the other-coupled to the spring members. The tie bars, experience has shown tend to minimize the rechtendency, but do not satisfactorily overcome the tendency ot-the screento tilt ton ward That is it the position and stifiness of the tie bars compensates for the tilting under conditions kril -load specification of Letters JPatenti Patentedh'fom id this;

n ntatna tilled huguit er, rare. serial nastiness. v

ling, they will not do so it the load at mate r al passing over the screen is increased or diminished.

The present invention has for its object to 1 provide for screens oi this type an arrangement which will combine the advantages of both these forms and will give a more satisfactory and edicient device. This is done by providing adjustable attachment means tor -the fired points of the spring, so that although this part of the spring is stationary when the. machine is in operation, it is not 'immovably fired but is susceptible of adjustment. The means referred to consists oi any arrangement of elements to be placed till between the lower spring member and the c spring supporting bracket, whereby the spring can be placed and held in such a aosi tion as will counteract the tilting ten eney alluded to. a i a,

With these and other objects in view the invention consists in the combination and arrangement of parts'more fully set forth in thetollowing specification, illustrated in the accompanying'drawings and pointed out in the appendedi claims.

in the drawings, three terms are shown by way of example, it being understood that it do not limit myself to the specific constructions here illustrated but wish to avail myselt'of all modifications which will fall properly within the scope of the invention;

Referring to the drawings: Figure l is a side elevation, illustrating one embodiment o 0 Q n or the present EHVQHMORQ Fig. 2 is a section tahenon the line 2 -24% Fig. i. Fig, 3' is a tragmental detail of rnedilied form oil.

the invention. d is a fragmental detail a further modification Referring to the drawings 1 designates a suitable upri-ght'irameworln, to which is se cured by bolts 92 a stationary frame 3,, which is iournaled a shaltt, to which. is se-= cured a pair of multiple canrwheels ii, ar-' ranged to act on parallel bars bl connected by transverse bars i? forming the body of the screen teens. The mesh material 8 oi the screen is secured to suitable bars 9 and lit.

To the upper suriface of the trams bars 6' are liltl attached contact plates ll, which are acted upon by the multiple can wheela h elcwerisurtace oi the bars 8 the screen-frame are attached double bow springs 13, located" on opposite sides and composed of upper and lower members bows 14: and 15, connected at their extremities as shown at 16. The upper members of these springs are secured to the bars 6 by bolts 17 while the lower members are similarly secured by bolts 18 to a plate 20. A bracket 21 rigidly secured to the stationary frame 3,

is provided with a depending arm 22 to .whicha secondplate .23, similar in size and shape to plate 20, is integrally formed. The lower bracket plate .23 has a centrally lo- .catediboss or sleeve 23 formed with a screw threaded bore in which a screw 2-4: passes upwardly. The plate 20 to which the spring trally located recess member 15 is bolted is provided witha coli- The plate is .supported by the screw 24: the upper end of which has a bearing in the pocket or recess 15. A pair of adjusting screw bolts 25 are .provided, one on either side of the supporting bolt 24. Thesebolts pass through perforations in the upper plate 20 and similar ones in the lower plate 23; Two adjusting nuts 25*?are threaded onthe stems of each of the bolts25 and arrangedone on either "side of the plate 23.

Secured to the side bars of thestationary frame 3 are brackets 26 which are provided with inwardly projecting arms 27, occupying positions directly above the bars 6 of the screen frame. There are two of these ;brack-' .ets 26 on-each side of-the screen frame. In as these brackets are screws 28, whose lower extremities are engagedby-the :bars 6 of the screen frame and form stops to limit the upward movement of the screen frame when the latter is released by the cam-faces of the multiple cam wheelsb. :As the upward or reverse movement of the screen frame is suddenly checked by the stop screws 28, which are four in number as heretofore explained,

- the resulting sudden impact performs an important function in the screening of the material, as will be readily understood. At-

tention is called to the fact that by having they multiple cam-wheels centrally located 1,13. [By loosening ortightening-the other-of the adjusting bolts 25 the angle: of inclination of the spring support can be adjusted" about its central andsubstantially vertical.-

axis, or in other words, about its pivotal bearing on the upper end of the screw 24.

.By varying this adjustment to suit the needs of the differently weighted loads passing hirer the screen frame 6 the proper'angle for the latterlcan be obtained which .will obvitiate yaaasnay bn.th,e part.of.the.aereen of the boss 23.

to tilt forward. This construction permits of a sensitive adjustment of the supporting spring about its vertical axis and at the same time does not entail the use of guides or other structural features, which would preclude the screen frames being freely poised or floated. I

Fig. 3 illustrates a modified form of the application of the same principle. In this construction the lower plate 23 is dispensed with and the bracket end is formed with an interiorly threaded boss 23 through which the supporting screw 24: is threaded. This upper plate 20 to which the lower spring member 15 is riveted, is made of inverted U- shape with two depending arms 20 and 20 equidistantly spaced from the screw 24. Adjusting screws 25' pass through inwardly threaded bosses 25 located near the lower ends of said arms. vided 011 the screws 25. The inner end of each screw bears against the outer surface By alternately loosening and tightening the adjusting screw bolts 25 exactly the same eifect is produced as was accomplished in the form illustrated in Fig. 1.

still further modification is shown by way of example in Fig. 4:. In this form only one adjustin screw bolt 25 is provided and this is rigidly carried by the boss 23" and projects therefrom at right angles thereto. The plate 20 has only one depending arm which extends downwardly at one side of and parallel to the bolt 24 and is perforated to receive the end of the adjusting bolt 25 This bolt is provided with twolocking nuts 25.

The three forms illustrated all accomplish the same results and many others may be devised.

Having described my invention what I claim is: i

1. In combination an inclined screen, stop means for limiting the upward movement of said screen, means for moving the screen downwardly in a direction transversely to its plane, spring means sustaining the screen and for forcing the screen upwardly to abut against the stops, and means for adjusting the spring means to alter the resistance of the spring means relatively in respect to the upper and lower ends of the screen to thereby compensate for the tendency of the screen to tip out of its proper inclined position duo to the weight of the material passing over it,

substantially as described.

2. In combination an inclined screen, cam

Lock nuts 25 are promeans for giving successive downward movements to the, screen in a direction transverse to its plane, stops at the upper and lower ends of the screen for limiting its upward movement, and spring means for giving the screen its upward movement in a di- :reatien transverse toits plane, and means-for ltl nieaeia adjusting the spring means to vary the force of the upward thrust of the screen at its lnwer end in respect to that at its upper end.

3. lln combination an inclined. screen, means for giving successive downward movements to the screen in a direction transverse to its plane, a sprin of double bow shape for giving the screen its upward movement, the upper member of said spring being centrally connected with the screen about centrally thereof, means connected with the center of the lower bow of said spring for supporting the same, and means for canting said spring-in relation to its support to compensate for the tendency of the screen to tip out of its proper inclined position due to its load, substantially as described.

4:. lln combination an inclined screen,

means for giving successive downward movements to the screen in a direction transverse to its plane, a spring of double bow stops to compensate for the tendency of the screen to tip out of proper inclined position due to its load, substantially as described.

5. In combination an inclined screen, means for giving successive downward movements to the screen in a direction transverse to its plane, a spring of double bow shape having its upper member centrally connected -with the screen about centrally thereof, a bearing upon which the lower member of the spring bears pivotally at about its center, and adjusting means for canting said spring on said pivot bearing, substantially as described.

6. lln combination an inclined screen, means for giving the screen successive downward movements in a direction transverse to its plane, spring means for sustaining said screen and moving it upwardly, and means for varying the direction or distribution of pressure of said spring in relation to the normal plane of the screen to compensate for the tendency of said screen to tip under difierent loads, substantially as described.

lln testimony whereof, ll afix my signature in presence of two witnesses.

RANDALL P. AKJENS. Witnesses:

H. B. liownnn, LEQN E. Herman. 

